Double-acting pump



Jan. 8, 1946. v w. A. FiNLEY *72,392,655

,DOUBLE ACTING PUMP Filed No'v. 9, 1944 Finley f 9 INVENToR.

a Arran/vens'.

Patented Jan. 8, 19.46

Y UNITED STATES PATENT OFFICE e i v 2,992,655 Y DOUBLE-ACTING PUMP william A.' Finley, Valdosta, Ga. Application November 9, 194.4, seriai'No. 562,629 1c1eim (o1. 10a-'179) This invention relates to pumps designed primarily for use in forcing liquid spray material through the discharge nozzles of spraying machines employed in spraying growing plants.

An important object of the invention is to provide a pump of this character which will act to produce a continuous flow of the liquid being sprayed, thereby insuring against the possibility of missing plants, as the machine moves along the plant rows, during the spraying operation.

Another object of the invention is to provide a pump including a novel valved piston construction which will automatically close to permit liquid to lbe drawn into the pump cylinder on the suction stroke of the piston of the pump, the valve automatically opening to allow liquid to flow through the piston, admitting liquid above the piston on the downstroke of the piston, thereby maintaining high pressure within the pump, while pumping light liquids.

With the foregoing and other objects in view which will appear as the description proceeds, the invention consists of certain novel details of construction and combinations of parts hereinafter more fully described and pointed out in the claim, it being understood that changes may be made in the construction and arrangement of parts without departing from the spirit of the invention as claimed.

Referring to the drawing:

Figure 1 is an elevational view of a pump constructed in accordance with the invention.

Figure 2 is a fragmental longitudinal sectional view through the pump.

Referring to the drawing in detail, the pump cylinder is indicated by the reference character 5 and as shown, has external threads formed at the ends thereof. At the lower end of the cylinder 5, is a removable valve housing 6 which is formed with a partition 'I disposed intermediate the ends thereof, dividing the valve housing into an upper valve chamber and a lower receiving chamber.

The partition I is formed with a plurality of openings B through which liquid passes from the receiving chamber to the pump cylinder.

The reference character 9 designates a sleeve which is fitted over the lower end of the housing 6, the sleeve carrying the screen I0 which strains the liquid passing into the pump proper.

The valve housing is formed with internal threads adapted to cooperate with the external threads at one end of the cylinder 5, for securing the removable valve housing in position.

Rising from the partition 1, is the valve stem I I which has its lower end threaded in an opening formed in the partition 1. Mounted for movement longitudinally of the valve stem I I, is a disk valve I2, which is of a diameter to overlie the openings 8 to close the openings under normal conditions.

The valve I2 is held to its closed position by means of the coiled spring I3 which is mounted on the valve stem I I, the lower end of the spring resting directly against the valve I2, while the upper end thereof rests against the head I4 of th valve stem I I.

The pump piston embodies separable sections I5 and I6, the section I5 being formed with a threaded extension II on which the section I6 is positioned. The cup washers I8 are held between the sections l5 and I6 of the pump piston, and are held in spaced relation with each other by means of the spacing disk I9 which is also threaded on the extension Il of the piston section I5. These washers are positioned so that the free edges thereof are disposed in opposite directions, thereby properly packing the piston for operation in both directions.

As clearly shown by Fig. 2 of the drawing, the sections I5 and I6 of the piston are formed with central bores which are appreciably larger than the extension 20 of the piston rod 2I, so that liquid may pass upwardly between the extension 2l) and the piston proper.

The extension 20 is of a length greater than the length of the bore of the piston proper, so that the piston rod may move independently of the piston. At the lower end of the extension 20, is the valve 22 which is adapted to seat on the tapered end of the section I6 of the piston. The valve 22 is held in position on the extension 20, by means of the nut 23, and may be adjusted longitudinally thereof.

The upper end of the cylinder 5 is closed by means of the packing collar 24 that is threaded on the upper end of the cylinder, the collar 24 being provided with an opening through which the piston rod 2I operates.

The outlet pipe of the pump is indicated by the reference character 25, and has connection with the cylinder 5, at a point adjacent to the upper end of the cylinder.

The reference character 26 indicates a pressure valve which is spring-controlled and is adapted to maintain constant pressure upon the discharge line at all times, excessive pressure of the liquid being pumped being by-pas'sed through the valve 26.

From the foregoing it will be seen that upon a downward movement of the piston within its cylinder, the valve 22 will move away from its seat, allowing liquid to pass upwardly between the extension and piston. Upon the suction stroke of the piston, the valve l2 will be ele- 'vated from its seat, allowing liquid to pass into the Valve chamber1 from where the liquid will 5 be forced into the upper portion of the pump 'cylinder upon the downward movement of the piston. As the piston is reciprocated Within the cylinder, it will be obvious that with each stroke of the piston, .ligui-,dfhe forced'lfrorn the dis.- /10 charge pipesgs," fthrebylproviding a icoritiniliilSv ow of liquid through the discharge pipe and nozzles connected therewith, and which are not j shown in the present application. n

What is claimed is:

A double acting pump comprising `a gpuinptylf inder, a discharge pipe connetedwith-,th YKcyl-fl of the pump cylinder, a sectional piston operating Within the cylinder, a threaded extension on one of the sections of the piston, said piston` having a -central longitudinal bore, a Valve Yseat at the lower end of the. bore, a piston rod tted within the bore in spaced relation with the Wall thereof, providing a passageway through the piston, cup washers mounted on the sections of the piston, the free ends of the cup washers being disposed `vopllcisite directionsfa @spacing disk threaded i on 'the extension and' adapted @to engage the cups, holding the cups spaced apart, a Viyyva'rlve on one end f the piston rod adapted to -more against the valve seat controlling the pasy sage of 'iliqud through the central longitudinal lgoigeggf vthfeypiston, and means for restricting ,Vmoijement of the piston with respect to the rod.

WILLIAM A. FINLEY. 

